DualIndexHashObject can now enqueue saves to prevent repeated-save thrashing

PBot/DualIndexHashObject.pm

@@ -36,6 +36,7 @@ sub initialize {
     my ($self, %conf) = @_;
     $self->{name}     = $conf{name}     // 'Dual Index hash object';
     $self->{filename} = $conf{filename} // Carp::carp("Missing filename to DualIndexHashObject, will not be able to save to or load from file.");
+    $self->{save_queue_timeout} = $conf{save_queue_timeout} // 0;
     $self->{hash}     = {};
 }
 
@@ -107,6 +108,7 @@ sub save {
         return;
     }
 
+    my $subref = sub {
         $self->{pbot}->{logger}->log("Saving $self->{name} to $filename\n");
 
         if (not $self->get_data('$metadata$', '$metadata$', 'update_version')) {
@@ -121,6 +123,19 @@ sub save {
         open(FILE, "> $filename") or die "Couldn't open $filename: $!\n";
         print FILE "$json_text\n";
         close FILE;
+    };
+
+    if ($self->{save_queue_timeout}) {
+        # enqueue the save to prevent save-thrashing
+        $self->{pbot}->{timer}->replace_subref_or_enqueue_event(
+            $subref,
+            $self->{save_queue_timeout},
+            "save $self->{name}",
+        );
+    } else {
+        # execute it right now
+        $subref->();
+    }
 }
 
 sub clear {

PBot/PBot.pm

@@ -258,6 +258,13 @@ sub initialize {
 
     # give botowner all capabilities
     $self->{capabilities}->rebuild_botowner_capabilities();
+
+    # flush all pending save events to disk at exit
+    $self->{atexit}->register(sub {
+            $self->{pbot}->{timer}->execute_and_dequeue_event('save *');
+            return;
+        }
+    );
 }
 
 sub random_nick {